1. Field of the Invention
The invention relates to a clamping element for setting or fixation of a bone fracture as well as to a setting device comprising such a clamping element. The invention also relates to a method for producing such a clamping element.
2. Discussion of Background Information
When a bone fracture is immobilized insufficiently, a callus formation, i.e. a tyloma-like thickening of the ends of the fracture from overgrowing bone tissue, can occur. In order to avoid such an indirect fracture healing via a callus, bone plates are used which are applied and attached to the outer surface of a broken bone so that the fracture site is set, i.e. fixed, during the healing process.
For such applications for the treatment of bone fractures, from prior art there are mainly known rigid, metallic bone plates formed in a planar manner and having bores which are screwed at the opposite sides of a fracture. For the fastening of such settings or fixations, usually so-called cortical screws are used which are screwed into the outer bone tissue, the so-called cortical layer, which has the highest strength of the bone. The setting or fixation ensures that the ends of the fracture cannot move with respect to each other and that newly formed bone tissue can accumulate such that it will not be subjected to any loads.
Furthermore, it is assumed that the healing process of a fracture can be influenced beneficially when a compression is applied onto the joined fracture site. Thereby a particularly close adaption, i.e. a very small clearance over which the ends of the fracture grow towards each other again, is effected.
With respect thereto, U.S. Pat. No. 7,763,056 B2 discloses a two-part bone plate, the two halves of which can move towards each other by means of an axial guide. For the production of a compression, various arrangements of tension springs are proposed which are fixed at the two halves. The bone plate is constructed of several components and, consequently, is cost-intensive to produce.
Furthermore, there are also known vertebral bone plates which are not completely rigid but enable a mutual approaching of vertebral bodies and a swinging or twisting of the vertebral bodies with respect to each other to a limited extent. Thereby for example the regeneration of a damaged intervertebral disk or the healing of a fracture of a vertebral body can be assisted. With respect thereto, the utility model specification DE 200 01 879 U1 and the published patent application WO 2004/034916 A1 disclose bone plates with sections which are shaped in a meandering manner and which furnish the structure of the bone plate with a multidirectional flexibility.
Furthermore, the published patent application WO 2005/086708 A2 describes various embodiments of bone plates for the anterior cervical spine, which enable an axial and a lateral flexibility and which have a structure with intermediate sections which, when subjected to a load in the axial direction, bend laterally.
Such vertebral bone plates which are known from prior art shall, however, prevent any compression between two vertebral bodies in order to relieve the intervertebral disk and to prevent any impairment or damage of the spinal nerves. Consequently, they are not suitable for a compression-producing setting of a bone fracture, and, moreover, due to the manifold requirements of said particularly delicate application, they have a complex structure. Also the bone plates cited at the beginning are of a relatively complex design and, correspondingly, are cost-intensive to produce.
Accordingly, in medical care only a limited circle of patients or of types of fractures has benefited from the advantageous application of a compression-producing setting until now.
Thus, the invention is based on the object to provide a clamping element for a setting or fixation device that can be produced at particularly low costs in order to expand the field of application of compression-producing settings or fixations, and on the object to develop a corresponding method by means of which the clamping element can be produced at low costs. Moreover, the invention is also based on the object to provide a setting or fixation device in which the clamping element can be used.